Buggy code:
public abstract class DefaultCompilerAdapter implements CompilerAdapter , CompilerAdapterExtension { private static final int COMMAND_LINE_LIMIT ; private static final FileUtils FILE_UTILS = FileUtils . getFileUtils ( ) ; protected Path src ; protected File destDir ; protected String encoding ; protected boolean debug = false ; protected boolean optimize = false ; protected boolean deprecation = false ; protected boolean depend = false ; protected boolean verbose = false ; protected String target ; protected Path bootclasspath ; protected Path extdirs ; protected Path compileClasspath ; protected Path compileSourcepath ; protected Project project ; protected Location location ; protected boolean includeAntRuntime ; protected boolean includeJavaRuntime ; protected String memoryInitialSize ; protected String memoryMaximumSize ; protected File [ ] compileList ; protected Javac attributes ; protected static final String lSep = StringUtils . LINE_SEP ; public void setJavac ( Javac attributes ) { } public Javac getJavac ( ) { } public String [ ] getSupportedFileExtensions ( ) { } protected Project getProject ( ) { } protected Path getCompileClasspath ( ) { } protected Commandline setupJavacCommandlineSwitches ( Commandline cmd ) { } protected Commandline setupJavacCommandlineSwitches ( Commandline cmd , boolean useDebugLevel ) { } protected Commandline setupModernJavacCommandlineSwitches ( Commandline cmd ) { setupJavacCommandlineSwitches ( cmd , true ) ; if ( ( ( attributes . getSource ( ) ) != null ) && ( ! ( assumeJava13 ( ) ) ) ) { cmd . createArgument ( ) . setValue ( "-source" ) ; String source = attributes . getSource ( ) ; if ( ( source . equals ( "1.1" ) ) || ( source . equals ( "1.2" ) ) ) { cmd . createArgument ( ) . setValue ( "1.3" ) ; } else { cmd . createArgument ( ) . setValue ( source ) ; } } else if ( ( ( ( assumeJava15 ( ) ) || ( assumeJava16 ( ) ) ) || ( assumeJava17 ( ) ) ) && ( ( attributes . getTarget ( ) ) != null ) ) { String t = attributes . getTarget ( ) ; if ( ( ( ( t . equals ( "1.1" ) ) || ( t . equals ( "1.2" ) ) ) || ( t . equals ( "1.3" ) ) ) || ( t . equals ( "1.4" ) ) ) { String s = t ; if ( t . equals ( "1.1" ) ) { s = "1.2" ; } <START_BUG> setImplicitSourceSwitch ( ( ( assumeJava15 ( ) ) || ( assumeJava16 ( ) ) ? "1.5<seq2seq4repair_space>in<seq2seq4repair_space>JDK<seq2seq4repair_space>1.5<seq2seq4repair_space>and<seq2seq4repair_space>1.6" : "1.7<seq2seq4repair_space>in<seq2seq4repair_space>JDK<seq2seq4repair_space>1.7" ) , cmd , s , t ) ; <END_BUG> } else if ( ( assumeJava17 ( ) ) && ( ( t . equals ( "1.5" ) ) || ( t . equals ( "1.6" ) ) ) ) { setImplicitSourceSwitch ( "1.7<seq2seq4repair_space>in<seq2seq4repair_space>JDK<seq2seq4repair_space>1.7" , cmd , t , t ) ; } } return cmd ; } protected Commandline setupModernJavacCommand ( ) { } protected Commandline setupJavacCommand ( ) { } protected Commandline setupJavacCommand ( boolean debugLevelCheck ) { } protected void logAndAddFilesToCompile ( Commandline cmd ) { } protected int executeExternalCompile ( String [ ] args , int firstFileName ) { } protected int executeExternalCompile ( String [ ] args , int firstFileName , boolean quoteFiles ) { } protected void addExtdirsToClasspath ( Path classpath ) { } protected void addCurrentCompilerArgs ( Commandline cmd ) { } protected boolean assumeJava11 ( ) { } protected boolean assumeJava12 ( ) { } protected boolean assumeJava13 ( ) { } protected boolean assumeJava14 ( ) { } protected boolean assumeJava15 ( ) { } protected boolean assumeJava16 ( ) { } protected boolean assumeJava17 ( ) { } protected Path getBootClassPath ( ) { } protected String getNoDebugArgument ( ) { } private void setImplicitSourceSwitch ( String defaultDetails , Commandline cmd , String target , String source ) { } }

Fix:
setImplicitSourceSwitch ( ( ( assumeJava15 ( ) ) || ( assumeJava16 ( ) ) ? "1.5<seq2seq4repair_space>in<seq2seq4repair_space>JDK<seq2seq4repair_space>1.5<seq2seq4repair_space>and<seq2seq4repair_space>1.6" : "1.7<seq2seq4repair_space>in<seq2seq4repair_space>JDK<seq2seq4repair_space>1.7" ) , cmd , t , s ) ;